The present disclosure relates to a device for correcting a sensor signal, a method for correcting a sensor signal, and a corresponding computer program product.
A nonlinearity in the force feedback of a microelectronic sensor (MEM sensor) reduces the noise performance of such a force-compensated sensor. Nonlinearities can arise from various effects, for example when use is made of a plurality of feedback electrodes, or else when there is voltage feedback with a plurality of voltage values given a capacitive converter element. This is circumvented in general in the case of capacitive converters by using PWM feedback (PWM=pulse width modulation) instead of voltage feedback. As a result, there are only two force states which, of course, always have a linear relationship. However, this approach has the disadvantage that the time steps have to be very small when high quantization is required. For example, should the feedback force be quantized with 10 bit, the sub-clock would need to be approximately 400 MHz given a sampling rate of 400 kHz. This is not sensible in terms of technology and limits the feedback quantization to a few bits in the case of PWM.
In the dissertation entitled “Dynamische Regelung mikroelektromechanischer Systeme (MEMS) mit Hilfe kapazitiver Signalwandlung and Kraftrückkopplung” [“Dynamic control of microelectromechanical systems (MEMS) with the aid of capacitive signal conversion and force feedback”] by Martin Handtmann, submitted to the TU Munich on Oct. 1, 2002, various approaches to the dynamic control of microelectromechanical systems are presented.